1. Field of the Invention
This application relates to the control and management of cooling airflow in computer data centers.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
The cooling of computer servers in data centers, sometimes termed “IT or electronic servers”, presents significant problems in efficient energy consumption. The computer servers typically are stacked on shelves in enclosed racks or cabinets some up to seven feet high, three feet wide, and four feet deep. Doors on the front and back sides of the racks retain the servers in the racks and control access to the servers. The front and back doors of the racks are perforated so that cooling air enters through the perforations in the front door, flows over the enclosed computer server, thereby cooling the heat generating processors, and the now heated air exits through the rear door of the rack. Racks are aligned in a data center in arrays of 15 to 20 racks in such a manner that all the front doors of the racks are on the same side of the array. Two parallel arrays of racks with the front doors facing each other constitute a “cold aisle.” The rear doors of racks in each array are adjacent to the rear doors of a parallel array with the space between the rear doors of the arrays constituting a “hot aisle.” The aisles allow access to the front doors and to the rear doors of the racks for purposes of inspection, maintenance, or replacement, of the computer servers contained within the racks.
Cooled air is introduced into a cold aisle, typically through perforated floor tiles in a raised access floor or through overhead ductwork. The cooled air within the cold aisle is drawn into the perforations in the front doors by fans in the computer servers; the air cools the computers; and the now heated air is extruded through the perforated back door into the hot aisle. Such heated air is then cooled by air conditioning apparatus and returned to the cold aisle or simply extruded from the data center.
The above cold aisle-hot aisle system suffers significant inefficiencies which stem from the mixing and recirculation of air between the cold aisle and the hot aisle over the top of the racks. The energy expended in the cooling of air which mixes above the racks is wasted, as that cooled air never is used to cool the computer servers.
A variety of containment approaches have been proposed to reduce or remove this inefficiency. The containment situation is complicated by the requirement that the space above the racks be free of obstructions for the proper flow of water from automatic sprinklers activated in case of a fire event. The following prior art represent approaches to solving this problem.
U.S. Pat. No. 6,672,955 discloses an Internet Data Center with a plenum below the floor for fresh air which opens to a cold aisle tunnel. Heated air freely flows upward from the hot aisle and is collected at a plenum at the top of the Center.
U.S. Pat. No. 7,403,391 discloses a data center with a number of embodiments, all of which involve a cooling unit positioned adjacent to a rack. In some embodiments flat or curved panels are located at the top of the racks, which restrict but don't prevent airflow between aisles.
U.S. Pat. No. 7,542,287 discloses racks which are fully enclosed except for the front side which admits cooled air and with ducts at the top for removal of heated air.
U.S. Pat. No. 7,667,965 discloses acoustically absorptive vertical anti-recirculation panels fixed by L shaped brackets to tops of adjacent racks.
U.S. Pub. Pat. Applic. No. 2006/0260338 discloses a system of baffles, doors, and slanted baffles attached to the top of racks to impede the horizontal flow of warm air from a hot aisle to a cold aisle.
U.S. Pub. Pat. Applic. No. 2009/0173017 discloses partitions on the tops of racks which are normally in the vertical position to inhibit unwanted airflows. The partitions are hinged at the attachment to the rack and are supported by guy-wires with fusible trigger-point assemblies which releases the partitions at a predetermined temperature, allegedly restoring the unrestricted gap between rack top and ceiling required by the fire-code.
U.S. Pub. Pat. Applic. No. 2010/0000953 discloses modular blocking panels which close off unused sections of a rack.
U.S. Pub. Pat. Applic. No. 2010/0061057 discloses modular panels which extend from adjacent racks to form a ceiling over a hot or cold aisle.
U.S. Pub. Pat. Applic. No. 2010/0108272 discloses a curtain-like roll-up air barrier with a spring-loaded roller fastened to the ceiling and with the bottom fastened to a hold down structure located on top of an IT rack. Water soluble loops fasten the barrier to the hold down structure and are designed to release the barrier when wetted by a sprinkler system.
U.S. Pub. Pat. Applic. No. 2010/0190430 discloses a computer room air conditioning system with a physical separation on the top of racks separating the hot and cold aisles.
None of the discovered prior art solves the problems solved by embodiments of the present disclosure. In particular, embodiments solve the problems of preventing mixing of cooled and heated air above the racks while meeting the fire suppression requirements, and have the further advantages of allowing installation, inspection, replacement, or maintenance of individual racks and servers contained within the racks without interruption to working data centers. In addition, embodiments can be installed without the requirement of interruption to working racks and the IT servers within the racks.
The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.